You will need to pip install openCV and PySimpleGUI

pip install opencv-python
pip install pysimplegui

Run any of the .py files in the top level directory:

yolo.py - single image processing
yolo_video.py Video display
yolo_video_with_webcam.py - webcam or file source. Option to write to hard drive

And you'll need the training data. It's 242 MB and too large for GitHub: https://www.dropbox.com/s/uf00d4ov6fmw0he/yolov3.weights?dl=1

This code has an article associated with it that will step you through the code (minus GUI part).

https://www.pyimagesearch.com/2018/11/12/yolo-object-detection-with-opencv/

This software is provided by Dr. Adrian Rosebrock of the pyimagesearch organization. https://www.pyimagesearch.com